So, one thing we found today is that GLES 2 in Godot 3.2 supports CanvasItemMaterials, which allows adding blend modes to sprites. I think that this function was not available in previous Godot version, but I am not sure. Either way, we just found out about it.
Until now, we thought that only GLES 3 supports blend modes, together with more advance glow effects. In general, using GLES 3 made the game look much better than GLES 2, with brighter colors and more realistic lighting. Unfortunately, it also completely ruined the performance on lower end mobile devices, which we are targeting as well.
Therefore, we had to fake glowing lights in the game using sprites, but the final result was not too great. Especially since we use the Modulate function to change the color of the lights in game.
Here is an example of how they used to look:
And how much of a difference using blend modes makes:
The foreground colors interact and blend with the background colors, creating, in my opinion, a much better effect.
Same result for this newly made asset.
Before:
After:
Overall I am pretty satisfied considering the negligible performance impact.